Gitlab runner in docker - Cannot connect to the Docker daemon at tcp://dind:2375

Question

I know this could be taken as a duplicate but I have tried everything I have found on the internet with no success.

I'm trying to set up a local gitlab-ce server on Windows using the Docker Desktop, but I'm not experienced enough to solve this error. I'm probably not understanding the situation very well.

I installed gitlab runner and registered it via Docker Compose. Here's the file:

services:
  dind:
    container_name: dind
    image: docker:25.0.3-dind
    restart: unless-stopped
    privileged: true
    environment:
      DOCKER_TLS_CERTDIR: ""
    command:
      - --storage-driver=overlay2
    networks:
      - playground
    volumes:
      - D:/Playground/data/gitlab-runner/dind:/var/lib/docker

  runner:
    container_name: runner
    image: gitlab/gitlab-runner:alpine-v16.9.0
    restart: unless-stopped
    environment:
      - DOCKER_HOST=tcp://dind:2375
    networks:
      - playground
    volumes:
      - D:/Playground/conf/gitlab-runner:/etc/gitlab-runner:z

  register-runner:
    container_name: registerrunner
    image: gitlab/gitlab-runner:alpine-v16.9.0
    restart: 'no'
    depends_on:
      - dind
    environment:
      - CI_SERVER_URL=http://gitlab.playground.local/
      - RUNNER_TOKEN=...
    command:
      - register
      - --non-interactive
      - --url=http://gitlab.playground.local/
      - --token=...
      - --name=Runner
      - --executor=docker
      - --docker-image=docker:25.0.3-dind
      - --docker-volumes=/var/run/docker.sock:/var/run/docker.sock
    networks:
      - playground
    volumes:
      - D:/Playground/conf/gitlab-runner:/etc/gitlab-runner:z
      - D:/Playground/data/gitlab-runner/dind:/var/lib/docker
networks:
  playground:
    name: playground
    driver: bridge

And my config.toml:

concurrent = 1
check_interval = 0
log_level = "debug"
log_format = "text"
connection_max_age = "15m0s"
shutdown_timeout = 0

[session_server]
  session_timeout = 1800

[[runners]]
  name = "Runner"
  url = "http://gitlab.playground.local/"
  id = 34
  token = "..."
  token_obtained_at = 2024-02-22T03:30:08Z
  token_expires_at = 0001-01-01T00:00:00Z
  executor = "docker"
  [runners.cache]
    MaxUploadedArchiveSize = 0
  [runners.docker]
    host = "tcp://dind:2375"
    tls_verify = false
    image = "docker:25.0.3-dind"
    privileged = true
    disable_entrypoint_overwrite = false
    oom_kill_disable = false
    disable_cache = false
    volumes = ["/var/run/docker.sock:/var/run/docker.sock", "/cache"]
    cache_dir = "cache"
    shm_size = 0
    network_mtu = 0

The http://gitlab.playground.local is conveniently defined in the Windows host file and I can access the instance. The problem is with the runner.

I can see the active runner in my gitlab instance, but when I run the pipeline I constantly get the following error:

ERROR: Failed to remove network for build
ERROR: Preparation failed: Cannot connect to the Docker daemon at tcp://dind:2375. Is the docker daemon running? (docker.go:933:12s)

I've already exposed the daemon on tcp://localhost:2375 without TLS in Docker, as I have seen in other threads with similar problems, but nothing changed.

Edit: more info added below

I've basically played a lot of trial and error up to the current setup. Among other things, I already tried not to use Docker-in-Docker and reduce the complexity, but I also got an exception. I also tried to cover permissions using usermod -aG docker gitlab-runner, but alpine doesn't have the usermod command, so I added the attribute user: 2000:2000 in the docker compose file as suggested here, but again without success.

I really believe (it's more of a hope than a certainty) that my configuration is not far from correct, but there is something that escapes me and I don't know what it is.

What am I missing?